[Q] Cyanogen: Set net.hostname at boot

---

Android 2.2 sets the default hostname to android_dfhjkahdjksf or something equally useless.
To override this in Cyanogen 6.1 you need to set the net.hostname property with setprop Eg:

# setprop net.hostname mickey

My problem is when I try to set this up at boot, something always overwrites my change with the default. I have tried putting it in my init.rc, /etc/init.d and /data/local/userinit.sh and it is always reset to default by the time the phone has booted.

Does anyone have any more ideas about how to permanently set the hostname? It would be a good option to have in cyanogenmod.

UP. I'm very interesting too.

The root filesystem is stored in the boot.img and is expanded to a ramdisk every time you reboot. For changes to be permenant, you need to extract the boot.img file, extract the kernel and ramdisk sections, modify the ramdisk image with your changes, then recombine the kernel and ramdisk to a new boot.img and reflash it. You'll probably need to do this on a linux machine that understands unix permissions and ramdisk/cpio filesystems as well as having a good knowledge of linux and unix commands. See this thread:

http://forum.xda-developers.com/showthread.php?t=551711

note: your kernel may use a different "--base 0x19200000" option when building the kernel boot image.

Is there not a way to add a correlating line to the build.prop file?

EDIT: This doesn't work - whatever is setting the net.hostname writes out after build.prop is read.

I'm looking...

I did a search in the /system/etc directory for any file doing setprop (I'm using a miui rom) and found the following script. I did the setprop for net.hostname in there and it too is being overwritten.

search command:

grep -H -r setprop /system/etc


/system/etc/init.goldfish.sh

I'm running out of ideas other than using autostart to set it after reboot.

EDIT2: doh. I think I already knew this but it dawned on me that the default net.hostname comes from concatenating the "android_id" (found in the secure database table) to the end of "android_".

So seems more likely to reset it after reboot using a script (gscript to launch it manually or use autostart to launch it automatically at the end of reboot cycle).

Property net.hostname originate from services.jar (ConnectivityServices.java):

// setup our unique device name
String id = Settings.Secure.getString(context.getContentResolver(), Settings.Secure.ANDROID_ID);
if (id != null && id.length() > 0) {
    String name = new String("android_").concat(id);
    SystemProperties.set("net.hostname", name);
}

Maybe CM guys would change this to add another "if /proc/sys/kernel/hostname is different than localhost, use it for net.hostname too" condition.

I'm not using CM so it is up to you guys to make a feature request.

Another approach would be to set service in init.rc that would start your net.hostname changing script on some property being set just after net.hostname is set. You could use also:

on property:net.hostname=android_blahblah

...but that wouldn't be so handy since you will have to change that line in init.rc every time you make a factory reset.

Really interesting, thx !

Originally Posted by BlaY0

Property net.hostname originate from services.jar (ConnectivityServices.java):

// setup our unique device name
String id = Settings.Secure.getString(context.getContentResolver(), Settings.Secure.ANDROID_ID);
if (id != null && id.length() > 0) {
    String name = new String("android_").concat(id);
    SystemProperties.set("net.hostname", name);
}

Maybe CM guys would change this to add another "if /proc/sys/kernel/hostname is different than localhost, use it for net.hostname too" condition.

I'm not using CM so it is up to you guys to make a feature request.

Another approach would be to set service in init.rc that would start your net.hostname changing script on some property being set just after net.hostname is set. You could use also:

on property:net.hostname=android_blahblah

...but that wouldn't be so handy since you will have to change that line in init.rc every time you make a factory reset.

Thanks a lot. I've been looking for this for the past hour or so. Traditional linux methods to set the hostname don't work... I think I'll add an option in cyanogenmod settings for this and submit it to Gerrit. Look for it to show up within the next day or two.

That's great m8! Cheers

Sent from my HTC Legend

underscores in hostnames are bad

---

The main thing I want to do is get rid of that underscore. Several of the places I hook up with with WiFi attempt to enter the hostname supplied during the DHCP conversation into a DNS. But underscore is illegal for this purpose.

Numbat.

Questions or Problems Should Not Be Posted in the Development Forum
Please Post in the Correct Forums

Moving to Q&A